The girl who feels no pain
Avid readers may have come across this condition in Stieg Larsson's Millennium Trilogy. The heroine, Liesbet Salander's evil half-brother, Ronald Niedermann, suffered (in his case it was a boon) from a rare condition where he felt no pain. But unlike the fictitious plot, this condition is for real, and it is known as hereditary sensory autonomic neuropathy (HSAN) type V.
A young US girl, Gabby Gingras, is reported to be living with it, and constantly and unwittingly injures herself – sometimes quite seriously.
Gabby's lack of pain sensation eventually led to the loss of all her teeth, and a badly scratched cornea forced doctors to remove her left eye. Now she wears a helmet and goggles every day to protect herself from serious injury.
Gabby's lack of pain sensation eventually led to the loss of all her teeth, and a badly scratched cornea forced doctors to remove her left eye. Now she wears a helmet and goggles every day to protect herself from serious injury.
Gabby's parents have started a foundation called 'Gift of Pain', a support group for people with HSAN. So far they have found 39 people who think they have the condition.
Women who have 200 orgasms a day

The sensations, which are not brought about by fantasies or other sexual thoughts, are often partially relieved through orgasm. For some women, even sex does not help quell their arousal, and on occasion can even make the sensation worse.
PSAS was only named in the medical fraternity in 2001, and very few women have been diagnosed. However, doctors believe that thousands of women may be suffering from this disease but may be too embarrassed to seek professional help.
Doctors are unable to find the underlying cause of this condition, and one woman with PSAS says that she has been to every doctor imaginable – gynaecologist, psychologist, psychiatrist – without satisfaction.
The man who never feels cold

Dr Ken Kamler, author of Surviving the Extremes, believes that Hof's ability lies in the wiring of his brain. "It's very easy to speculate that the same mind control that you use to control your heart when you're scared also can be called upon to control the other organs in the body," he told ABC News Medical Unit.
Foreign accent syndrome

This condition has only been reported a handful of times. The most well-known case is that of a Norwegian woman who sustained a head injury during World War II air-raid bombings in 1941 and began to speak with a German-like accent. Because of her speech she became the target of anti-German sentiment.
More recent cases include a 52-year-old Canadian woman who started talking in a distinctly eastern dialect after she suffered a stroke in 2006; two American women, who started speaking with British and French accents respectively; and then a Japanese women who started speaking with a Korean accent.
The syndrome was once regarded as a psychological disorder, but it's now thought to be a neurological problem, which comes about when an injury or stroke damages the part of the brain associated with speech.
The tree man

In 2007, Kosawa had 5.5kg of warts removed at an Indonesian hospital and regularly undergoes more surgery to remove new warts that have grown back. After the initial surgery he has better use of his hands and feet, but will continue to undergo surgery every few months, as there is no known cure for his condition.
Water allergy

The condition, known as Aquagenic Urticaria, is very rare and was first diagnosed in 1964. Currently an Australian teenager from Melbourne is reported to be living with this strange disease.
The boy who couldn't sleep

Once diagnosed, doctors were able to perform a risky surgery that offered a 50-50 chance Rhett would be able to sleep normally for the first time. The surgery was successful and Rhett was finally able to sleep through the night, and his behaviour improved dramatically.
Because of the disease, he was functioning at the level of an 18-month-old and couldn’t even speak. But in a matter of months, he has almost caught up to his peers, and for the first time in his life, he is interacting with other children.